Electronic discharge tube



July 4, 1939. A; GAI-:BEL ET Al.

vmfacTRoNIc: DISCHARGE TUBE Filed Jan. 16, 1957 @rvu-'wv Patented July 4, 1939 UNITED STATES PATENT OFFICE ELECTRONIC DISCHARGE TUBE Alfred Gaebel, Berlin,

Berlin-Lichterfelde, Germany,

and Annemarie Katsch,

assignors to C.

Lorenz Aktiengesellschaft, Berlin-Tempelhof, Lorenzweg, Germany, a company 3 Claims.

The invention relates to electronic discharge valves or tubes of the kind in which an electrode or several electrodes are formed integral with a portion located outside the .discharge Vessel and united with the wall thereof.

When melting glass or a ceramic glazing or the like onto the butt joint which there is between such an electrode portion and the wall of the vessel, difculty is encountered by the electrode carrying away the heat from the melting spot in a manner to impair the effect of melting.

The invention obviates this by so constructing the electrodes that the path from the melting spot to the main body of the electrodes shall be as large as possible.

One embodiment of the invention is described hereafter, reference being had to the accompanying drawing that shows a partially diagrammatic sectional view thereof.

In this drawing, A denotes the anode, K the cathode, G the grid which in the case represented by way of example is a wire helix whose turns E, F are supported by shanks E, F in a well known manner. These are fastened in a socket 3 of a metal Adisc B, this disc thus supporting the grid G by means of the shanks E1, F. Cathode K is arranged to extend through socket 3. Anode A has cooling fins W the two outer of which are each integral with a ring P.

The discharge vessel D is composed of ceramic portions Wl, W2, W3 and a glass top U. The portions Wl, W2 are held together by a metal ring Q. Equally, the portions W2, W3 are held together with the aid of the two rings P. Portion U is provided with a tubular extension u. where the vessel is connected with the pump and where it is sealed off, as is well known with devices of this kind. Glass portion U is united with the ceramic portion W3 by melting.

In order to provide for airtightness the ceramic portions WI W2, W3 are shaped outside by grinding so as to intimately contact with the rings P, Q. The airtightness afforded in this way is raised to vacuum tightness by melting glass or a ceramic glazing or the like onto the telescopic or lap joints so as to produce melting spots S.

Ring Q, or any other ring of similar disposition, may form one coating of a condenser C whose other coating is a metal ring 2, an annular dielectric 4 being arranged between the two.

In order now to avoid that during the process of producing the melting spots S too much heat is carried away by the electrodes concerned, the invention provides for the path between the spots S and the main body or active part of the electrodes being calculated to be as large as possible. This is only shown in connection with the anode A since among the electrodes of a discharge tube body through said (Cl. Z-27.5)

the anode is of the largest quantity of metal. It is to be understood however that the invention is applicable to other electrodes too.

In the example represented the said path is formed by the rings P and the cooling 1in W integral therewith, thus being long enough to prevent the heat from being carried away to an extent that would impair the effect of the melting.

In this way the flow of heat from the melting spots S is so reduced that the melting can be effected in a quick and reliable manner and that therefore the lap joints between the rings P and vessel D will not be subjected to unnecessary or harmful high temperatures.

What is claimed is:

l. An electronic discharge tube comprising two hollow tubular vessels of ceramic material disposed end to end to enclose a cavity, a metal body adapted to act as an electrode disposed in said cavity, two metallic disk-like flanges united with said electrode and extending outwardly therefrom beyond the periphery of said vessels, a metallic skirt united with each of said flanges and extending along the outer surface of one of said vessels to an annular sealing zone on said outer surface, and a fused seal along each said zone between said ceramic vessel and said skirt, the length of the metallic path from said body through said flange and said skirt to said sealing zone being sufliciently great in relation to the thickness of said flange and skirt to reduce the heat conductance between said sealing zone and said body to a value which permits the rapid heating of said sealing zone.

2. An electronic discharge tube comprising a vessel of ceramic material, a metal body adapted to act as an electrode disposed in said vessel, a metallic disk-like flange united with said electrode and extending outwardly therefrom beyond the periphery of said vessel, a metallic skirt united with said flange and extending along the outer surface of said vessel to an annular sealing zone on said outer surface, and a fused seal along said zone between said ceramic vessel and said skirt, the length of the metallic path from said flange and said skirt to said sealing zone being sufficiently great in relation to the thickness of said flange and skirt to reduce the heat conductance between said sealing zone and said body to a value which permits the rapid heating of said sealing zone.

3. An electron discharge tube according to claim 2 wherein said electrode is provided with at least one cooling iin extending from said body into the space exterior to said cavity intermediate said two metallic flanges.

ANNEMARIE KATSCH. ALFRED GAEBEL. 

